In dual slide high speed pneumatic feeders the valving there for and the valve actuation means have proved to be one of the most critical areas of such systems. The duplex rotary valve stock feeder illustrated in my prior U.S. Pat. No. 3,847,320 was found to be most effective in operating at very high cyclic rates; however the driving of this rotary type valve, through interfacing of the feeder with the associated punch press, presented some practical drawbacks. Here the rotary valve was required to continuously rotate in synchronism with the rotation of the main crank shaft of the punch press and this in turn necessitated a rather elaborate and relatively expensive interconnecting gear drive between said press crank shaft and the rotary valve. While such expensive mechanical interfacing apparatus and extensive set up time might be justified for long production runs for example those lasting several weeks, such would not be justified for a high speed but short production run that might last for only a few hours or a day or two.
Further as operative press speeds increase it is imperative that air consumption per cycle of the feeder be minimized, and that the structural arrangement for the feeder be made as compact and flexible as possible.
Finally in that piloted dies are often used in high speed stamping operations it has become apparent that a more reliable and efficient arrangement must be provided in the feeder to automatically release the feed grip on the stock immediately after the completion of each feed stroke of the feeder.